﻿using System;

namespace Common.NetWork
{
    /// <summary>
    /// 冒险岛key
    /// </summary>
    public class MapleAESOFB
    {

        private byte[] m_iv;
        /// <summary>
        /// 冒险岛版本
        /// </summary>
        private short m_MapleVersion;

        public short MapleVersion
        {
            get { return m_MapleVersion; }
            set { m_MapleVersion = value; }
        }

        private static byte[] funnybytes = new byte[] {(byte)0xEC,(byte)0x3F, (byte)0x77, (byte)0xA4, (byte)0x45, (byte)0xD0, (byte)0x71, (byte)0xBF, (byte)0xB7, (byte)0x98, (byte)0x20, (byte)0xFC,
          (byte)0x4B, (byte)0xE9, (byte)0xB3, (byte)0xE1, (byte)0x5C, (byte)0x22, (byte)0xF7, (byte)0x0C,	(byte)0x44, (byte)0x1B, (byte)0x81, (byte)0xBD, (byte)0x63, (byte)0x8D, (byte)0xD4, (byte)0xC3,
          (byte)0xF2, (byte)0x10, (byte)0x19, (byte)0xE0, (byte)0xFB, (byte)0xA1, (byte)0x6E, (byte)0x66,	(byte)0xEA, (byte)0xAE, (byte)0xD6, (byte)0xCE, (byte)0x06, (byte)0x18, (byte)0x4E, (byte)0xEB,
          (byte)0x78, (byte)0x95, (byte)0xDB, (byte)0xBA, (byte)0xB6, (byte)0x42, (byte)0x7A, (byte)0x2A, (byte)0x83, (byte)0x0B, (byte)0x54, (byte)0x67, (byte)0x6D, (byte)0xE8, (byte)0x65, (byte)0xE7,
          (byte)0x2F, (byte)0x07, (byte)0xF3, (byte)0xAA, (byte)0x27, (byte)0x7B, (byte)0x85, (byte)0xB0,	(byte)0x26, (byte)0xFD, (byte)0x8B, (byte)0xA9, (byte)0xFA, (byte)0xBE, (byte)0xA8, (byte)0xD7,
          (byte)0xCB, (byte)0xCC, (byte)0x92, (byte)0xDA, (byte)0xF9, (byte)0x93, (byte)0x60, (byte)0x2D,	(byte)0xDD, (byte)0xD2, (byte)0xA2, (byte)0x9B, (byte)0x39, (byte)0x5F, (byte)0x82, (byte)0x21,
          (byte)0x4C, (byte)0x69, (byte)0xF8, (byte)0x31, (byte)0x87, (byte)0xEE, (byte)0x8E, (byte)0xAD, (byte)0x8C, (byte)0x6A, (byte)0xBC, (byte)0xB5, (byte)0x6B, (byte)0x59, (byte)0x13, (byte)0xF1,
          (byte)0x04, (byte)0x00, (byte)0xF6, (byte)0x5A, (byte)0x35, (byte)0x79, (byte)0x48, (byte)0x8F,	(byte)0x15, (byte)0xCD, (byte)0x97, (byte)0x57, (byte)0x12, (byte)0x3E, (byte)0x37, (byte)0xFF,
          (byte)0x9D, (byte)0x4F, (byte)0x51, (byte)0xF5, (byte)0xA3, (byte)0x70, (byte)0xBB, (byte)0x14,	(byte)0x75, (byte)0xC2, (byte)0xB8, (byte)0x72, (byte)0xC0, (byte)0xED, (byte)0x7D, (byte)0x68,
          (byte)0xC9, (byte)0x2E, (byte)0x0D, (byte)0x62, (byte)0x46, (byte)0x17, (byte)0x11, (byte)0x4D,	(byte)0x6C, (byte)0xC4, (byte)0x7E, (byte)0x53, (byte)0xC1, (byte)0x25, (byte)0xC7, (byte)0x9A,
          (byte)0x1C, (byte)0x88, (byte)0x58, (byte)0x2C, (byte)0x89, (byte)0xDC, (byte)0x02, (byte)0x64,	(byte)0x40, (byte)0x01, (byte)0x5D, (byte)0x38, (byte)0xA5, (byte)0xE2, (byte)0xAF, (byte)0x55,
          (byte)0xD5, (byte)0xEF, (byte)0x1A, (byte)0x7C, (byte)0xA7, (byte)0x5B, (byte)0xA6, (byte)0x6F,	(byte)0x86, (byte)0x9F, (byte)0x73, (byte)0xE6, (byte)0x0A, (byte)0xDE, (byte)0x2B, (byte)0x99,
          (byte)0x4A, (byte)0x47, (byte)0x9C, (byte)0xDF, (byte)0x09, (byte)0x76, (byte)0x9E, (byte)0x30,	(byte)0x0E, (byte)0xE4, (byte)0xB2, (byte)0x94, (byte)0xA0, (byte)0x3B, (byte)0x34, (byte)0x1D,
          (byte)0x28, (byte)0x0F, (byte)0x36, (byte)0xE3, (byte)0x23, (byte)0xB4, (byte)0x03, (byte)0xD8, (byte)0x90, (byte)0xC8, (byte)0x3C, (byte)0xFE, (byte)0x5E, (byte)0x32, (byte)0x24, (byte)0x50,
          (byte)0x1F, (byte)0x3A, (byte)0x43, (byte)0x8A, (byte)0x96, (byte)0x41, (byte)0x74, (byte)0xAC,	(byte)0x52, (byte)0x33, (byte)0xF0, (byte)0xD9, (byte)0x29, (byte)0x80, (byte)0xB1, (byte)0x16,
          (byte)0xD3, (byte)0xAB, (byte)0x91, (byte)0xB9, (byte)0x84, (byte)0x7F, (byte)0x61, (byte)0x1E,	(byte)0xCF, (byte)0xC5, (byte)0xD1, (byte)0x56, (byte)0x3D, (byte)0xCA, (byte)0xF4, (byte)0x05,
          (byte)0xC6, (byte)0xE5, (byte)0x08, (byte)0x49};




        public MapleAESOFB(byte[] iv, int mapleVersion)
        {
            setIv(iv);
            this.MapleVersion = (short)(mapleVersion >> 8 & 0xFF | mapleVersion << 8 & 0xFF00);
        }

        public static byte[] getNewIv(byte[] oldIv)
        {
            sbyte[] inp = { -14, 83, 80, -58 };
            byte[] data = new byte[inp.Length];
            System.Buffer.BlockCopy(inp, 0, data, 0, inp.Length);
            for (int x = 0; x < 4; x++)
            {
                if (x == 2 && oldIv[x] == 120)
                {
                    int a = 0;
                }
                funnyShit(oldIv[x], data);
            }
            return data;
        }

        public static void funnyShit(byte inputbyte, byte[] inp)
        {
            byte elina = inp[1];
            byte anna = inputbyte;
            byte moritz = funnybytes[(elina & 0xFF)];
            moritz = (byte)(moritz - inputbyte);
            int tmp26_25 = 0;
            byte[] tmp26_24 = inp;
            tmp26_24[tmp26_25] = (byte)(tmp26_24[tmp26_25] + moritz);
            moritz = inp[2];
            moritz = (byte)(moritz ^ funnybytes[(anna & 0xFF)]);
            elina = (byte)(elina - (moritz & 0xFF));
            inp[1] = elina;
            elina = inp[3];
            moritz = elina;
            elina = (byte)(elina - (inp[0] & 0xFF));
            moritz = funnybytes[(moritz & 0xFF)];
            moritz = (byte)(moritz + inputbyte);
            moritz = (byte)(moritz ^ inp[2]);
            inp[2] = moritz;
            elina = (byte)(elina + (funnybytes[(anna & 0xFF)] & 0xFF));
            inp[3] = elina;

            int merry = inp[0] & 0xFF;
            merry |= inp[1] << 8 & 0xFF00;
            merry |= inp[2] << 16 & 0xFF0000;
            merry |= (int)(inp[3] << 24 & 0xFF000000);
            uint ret_value = (uint)merry >> 29;
            merry <<= 3;
            ret_value |= (uint)merry;

            inp[0] = (byte)(ret_value & 0xFF);
            inp[1] = (byte)(ret_value >> 8 & 0xFF);
            inp[2] = (byte)(ret_value >> 16 & 0xFF);
            inp[3] = (byte)(ret_value >> 24 & 0xFF);
        }


        public static int getPacketLength(int packetHeader)
        {
            int packetLength = packetHeader >> 16 ^ packetHeader & 0xFFFF;
            packetLength = ((packetLength << 8) & 0xFF00) | ((packetLength >> 8) & 0xFF);
            packetLength = ((packetLength << 8) & 0xFF00) | ((packetLength >> 8) & 0xFF);
            return packetLength;
        }

        public bool checkPacket(byte[] packet)
        {
            return (((packet[0] ^ this.m_iv[2]) & 0xFF) == (this.m_MapleVersion >> 8 & 0xFF)) && (((packet[1] ^ this.m_iv[3]) & 0xFF) == (this.m_MapleVersion & 0xFF));
        }

        public bool checkPacket(int packetHeader)
        {
            return checkPacket(new byte[] { (byte)(packetHeader >> 24 & 0xFF), (byte)(packetHeader >> 16 & 0xFF) });
        }

        private void setIv(byte[] iv)
        {
            this.m_iv = iv;
        }

        public byte[] getIv()
        {
            return this.m_iv;
        }

        public byte[] crypt(byte[] data)
        {
            updateIv();
            return data;
        }

        private void updateIv()
        {
            this.m_iv = getNewIv(this.m_iv);
        }

        public byte[] getPacketHeader(int length)
        {
            int iiv = (m_iv[3]) & 0xFF;
            iiv |= (m_iv[2] << 8) & 0xFF00;

            iiv ^= this.m_MapleVersion;
            int mlength = ((length << 8) & 0xFF00) | (length >> 8);
            int xoredIv = iiv ^ mlength;

            byte[] ret = new byte[4];
            ret[0] = (byte)((iiv >> 8) & 0xFF);
            ret[1] = (byte)(iiv & 0xFF);
            ret[2] = (byte)((xoredIv >> 8) & 0xFF);
            ret[3] = (byte)(xoredIv & 0xFF);
            return ret;
        }

    }
}
